Electric watch



6 Sheets-Sheet 1 INVENTOR JOHN A. VAN HORN PHILIP E.BIEMILLER JAMES H.REESE ATTORNEY June 2, 1959 J. A. VAN HORN ETAL ELECTRIC WATCH FiledFeb. 12. 1954 June 2, 1959 J. A. VAN HORN ETAL 2,888,797

ELECTRIC WATCH:

Filed Feb. 12, 1954 6 Sheets-Sheet 2 n l I /Q- 7/ N "*1 M n 2 u. a L a Mb 3 m /n m o m N as w rq- 3 3 i m m I l INVENTOR JOHN A. VAN HORN PHILIPE. BIEMILLER JAMES H. REESE ATTORNEY June 2, 1959 J. A. VAN HORN ETALELECTRIC WATCH 6 sheets-sheet 3 Filed Feb. 12, 1954 INVENTOR JOHN A.VPHILIP E.

N HORN EMILLER JAMES H. REE v ATTORNEY June 2, 1959 J. A. VAN HORN ETALELECTRIC WATCH 6 Sheets-Sheet 4 Filed Feb. 12. 1954 INVENTOR JOHN A. VANHORN PHILIP E. BIEMILLER JAMES H. REESE ATTOR EY June 1959 J. A. VANHORN ETAL 2,888,797-

ELECTRIC WATCH 6 Sheets-Sheet 5 Filed Feb. 12, 1954 KIT- INVENTOR JOHNA.VAN HORN PHILIP E. BIEMILLER JAMES H. REESE ATTORNEY June 2, 1959 J.A. VAN HORN ETAL 2,888,797

ELECTRIC WATCH I Filed Feb. 12, 1954 s Sheets-Sheet s LEAKAGE FIELDINVENTOR JOHN A.VAN HORN PHILIP E. BIEMILLER JAMES H. REESE ATTORNEYUnited States Patent ELECTRIC WATCH John A. Van Horn and Philip E.Biemiller, Lancaster,

and James H. Reese, Manheim, Pa., assignors t0 Hamilton Watch Company,Lancaster, Pa.

Application February 12, 1954, Serial No. 409,934

21 Claims. (Cl. 58-28) This invention relates to a wrist watch of smallsize in which the motive power is a battery contained within the watchcase and in which a moving coil passing through a magnetic field isenergized periodically by the battery to provide the power mechanism forthe Watch.

Heretofore, in attempts to make battery operated wrist watches, theproblem of obtaining sufficient energy to operate the watch for extendedperiods from a source which could be enclosed in a wrist watch casealong with the movement was insurmountable, and the maintaining of aclean and smooth contact provided difiiculties which could not beovercome in a practical manner.

The object of the present invention is to provide a wrist watch whichmay be operated by the power furnished from a battery small enough to beenclosed within the wrist watch case by attaining a sufiiciently highelectrical efiiciency.

It is a further object of the present invention to provide a batteryoperated wrist watch in which the electrical circuitry is of such anature that the voltages developed are comparatively small, and inparticular circuitry of sufiiciently low inductance that electricalerosion of the contacts when the circuit is broken is negligibly small.

' A further object of the present invention is to make use of the fieldfrom a permanent magnet and to pass through that field a coil, and toprovide means for energizing said coil during its passage through thefield to obtain an impulse which is imparted to the coil through apredetermined angle in its oscillatory movement in one direction and toprovide a hairspring for supplying a restoring torque resulting in anoscillatory movement of said coil.

It is a further object of the present invention to provide means formaking an electrical circuitbetween the oscillating coil and thestationary battery and to provide an oscillating contact which will havea wiping engagement through a portion of its angular movement to insurea clean and smooth contact.

It is a further object of the present invention to provide a means incombination with the battery powered oscillating balance wheel fortaking the oscillatory motion from the balance wheel and changing it tointermittent rotary motion in one direction and to do so with smallexpenditure of energy.

It is a further object of the present invention to provide anoscillating balance wheel and hairspring assembly, which balance wheelcarries a coil which is periodically energized by a battery containedwithin the wrist watch case and to oscillate said coil through amagnetic field created by permanent magnets, energizing the coil throughcontacts, one of which oscillates with said coil and en gages the othercontact through an angular distance not greater than the angulardistance the coil moves in passing through an intense portion of themagnetic field, and through a pair of intermeshed wheels to transfer theoscillatory movement of the balance wheel into intermittent rotarymotion in one direction and to further measure the extent of thatintermittent rotary motion by hands with a watch dial.

which carries a second pinion 29 and is journalled ice It is a stillfurther object of the present invention to provide permanent magnets andto bridge said magnets with a shunt spaced from the magnets to provideintensified magnetic fields and to oscillate a coil between the shuntand the permanent magnets, passing the coil through an intense portionof the magnetic fields between the shunt and the pair of magnets.

It is a still further object of the present invention to provide acontact making mechanism which will make contact, on movement of thecoil in one direction, with a predetermined pressure and through apredetermined angular distance and will swing clear of such contact uponoscillatory movement in the other direction, with only slight resistanceto the movement of said contacts necessary to swing it from engagementwith the oscillating contact.

It is a still further object of the present invention to provide a pairof intermeshed indexing gears used in combination with the oscillatorymovement of the balance wheel, the teeth of which gears are adapted tobe engaged by a jewel pin carriedby the balance staff for a movement ofthe gears of one half tooths distance, each of the gears moving in anopposite direction with means for taking from one of the gearsintermittent motion in a single direction.

These and further objects and advantages of the invention will becomemore apparent upon reference to the following specification and claimsand appended drawings in which:

Figure 1 is a top plan view of the wrist watch with the dial broken awayto show the setting mechanism.

Figure 2 is a bottom plan view of the watch with the back removedshowing the balance Wheel contact and battery assembly.

Figure 3 is a sectional view in two parts taken on a line of centerswhich shows in an extended line the Figure 12 is a sectional view online 12-12 of Figure 2.

Figure 13 is a section of the contact supporting bridge.

Figure 14 is a diagrammatic view of the permanent magnetic field,showing the flow of magnetic flux.

Figure 15 is a diagrammatic view of Figure 14 including the coil.

Figure 16 is an actual view of the magnets and shunt diagrammaticallyshowing the magnetic field.

Figure 17 is a top plan view of the coil showing the direction of flowof the magnetic flux during the energization of the coil.

Referring to the figures, a wrist watch case 16 encloses a dial 17 withhour hand 18, minute hand 19 and sweep second hand 20. The minute handis mounted on the cannon pinion 21 which is hollow and has a centralshaft 22 journalled therein to drive the sweep second hand 20. A trainof gears and pinions receives the motion from the index pinion 23. Afirst gear 24 journalled in an upper jewel 25 and supported by a lowerbearing 26 meshes with the index pinion 23 and carries first pinion 27which is in mesh with the second gear 28 the upper bearing and lowerbearing 31. The gear 24 is journalled on the shaft 22 carrying thesecond hand 20. A third gear 32 is in mesh with the pinion 29 and therelation between the gear 24 and the gear 32 is such that the gear 24turns sixty times as fast as the gear 32. The gear is staked to a hub 33which is extended to form a sleeve 34 which carries a cannon pinion 35.The cannon pinion 35 carries the minute hand 19 and also drives a gear36 and its pinion 37, which in turn drives the gear 38 carrying the hourhand 18.

A stem 39 having a crown 40 and a tooth gear 41 may be moved into andout of engagement with the gear 42 mounted on the shaft 43 and turninggear 44 which is in mesh with the gear 36. By turning the crown 40 withthe stem 39 pulled out so that the gear 41 is in mesh with the gear 42,the hands may be set to any desired position through the usual watchsetting mechanism.

The watch case 16 has a pillar plate 45 which may be cut out to receivea battery 46. The battery 46 has a bottom plate 47 by means of which thebattery is grounded to the pillar plate 45 and connected parts of thewatch. The pillar plate is cut away to receive a straight permanentmagnet 48 and a curved permanent magnet 49 which are held in place byscrews (not shown). These magnets have their ends bridged by a shunt 50supported on non-magnetic bridges 50, secured to the pillar plate 45 toprovide a pair of intensified magnetic fields 51 and 52 (Figure 12).

A balance cock 53 mounted on the pillar plate by a pair of screws 54 anda steady pin 55 supports an endstone and olived jewel assembly 56 inwhich is journalled one end of a balance staff 57. The other end isjournalled in a like assembly 58 mounted in the pillar plate 45. Thebalance stafi carries the usual hairspring 59 controlled by the usualregulating pins 60 and a balance wheel assembly 61 having an indexingroller 62 and a contact roller 63.

The balance wheel is formed with a substantially 8- shaped metal body 64which supports between one pair of its arms an electric coil 65, whilethe other pair of arms have their ends 66 extended inward to supportcounter-balancing screws 67. The coil has one end 90 grounded byconnection to the 8-shaped metallic body of the balance wheel. The coil65 together with portions of the framework 64 is embedded in aprotective plastic resin. The plastic resin allows the insertion ofweights 102 embedded in the plastic which may be used forcounterbalancing. The other end 91 is connected to a nut 92 (Figure 11)embedded in plastic casting. A screw 93 threaded into nut 92 makeselectrical connection with a contact strip 68 which is supported by aninsulated sleeve 69 carried on the contact roller 63. This contact 68oscillates with the balance wheel and is periodically brought intoengagement with a spring contact arm 70 secured to the extended end 71of a coil spring 72 by brazing, welding, soldering, or any suitablemeans.

The spring 72 is carried on a pin 73 having an enlarged head 74 whichhas a kerf 75 so that the pin and its supported spring may be orientedto any desired angular position. The pin is carried by friction in thesplit end 76 of a bridge 77 which is held to the pillar plate by screw78 and is connected to the battery through the wire 79. The end of thewire spring is extended upward through a hole 80 in the pin 74 andsoldered at 81 to provide electrical connection. The bridge 77 isinsulated from the pillar plate and screw 78 by a pair of insulatingwashers 82.

Referring particularly to Figures 6, 7, 8, 9, 10 and 11, the contact 68which is connected to one end of the coil is oscillated by the motion ofthe balance assembly 61. Carried by the contact roller 63 is anon-conducting jewel pin 83 which is adapted to contact the end portionof e e n n 71 of the spring 72 during the oscillating motion of thebalance assembly 61. Referring particularly to Figure 6 where motion isin a clockwise direction, the end of the spring wire 71 is free ofcontact with the pin 83 and at the same time the contact making arm 70is free of the contact of the contact strip 68. Figure 7 shows continuedmotion in a clockwise direction with the pin 83 engaging the extendedend 71 of the spring 72 flexing the entire length of the extended end 71and slightly opening the coils of the spring 72 so that the flexingmotion caused by contact of the pin when moving in a clockwise directionutilizes a very small amount of energy by reason of the ease with whichthe arm 71 is flexed due to the comparatively long length of wire andits connection with the coils of the spring.

Referring to Figure 8 where motion is in a counterclockwise direction,the pin 83 is about to engage the extended spring wire 71, the contactarm 70 being free of contact with the contact strip 68. Figure 9 showsthe engagement between the pin 83 and the arm 71 bringing the contactarm 70 into wiping engagement with the contact strip 68, the contactbeing maintained until the end of the wire 71 is freed from the pin 83by reason of the relative motion. The angular interval over whichelectrical contact is established can be altered by moving the pair ofwires 70 and 71 either along their length or at right angles to thisdirection in the plane perpendicular to the axis of rotation of thestaff 57 by rotation of the bridge 77 about the screw 78 or by rotationof the wires about the pin 74 or by bending the wires 70 and 71 andaltering the angle between them in the plane perpendicular to the axisof the staif 57. The same manipulations can be used to alter thepressure of the contact between the wire 70 and the contact strip 68,and it has been found in practice that a proper combination of thesemanipulations provides a range of variation of contact duration and ofcontact pressure which exceed those actually necessary. The contactpressure is also dependent upon the resilience of the wires 70 and 71which provides an additional adjustment.

The proper value of contact pressure is one which is great enough toinsure good electrical contact, but not so great as to provide excessiveinterference with the motion of the balance wheel. The angular intervalof contact should be chosen so as to provide the desired amplitude ofoscillation of the balance wheel, and the angular interval of contact islimited in its usable upper value by the spatial extent of theintensified magnetic fields 51 and 52.

Referring particularly to Figure 4, the lower or indexing roller 62carries an indexing pin 84 which oscillates with the balance wheel andbalance staff. Located .in the path of oscillatory movement of theindexing pin 84 are a pair of meshed indexing wheels 85 and 86. Arrangedat the outer circumference of one of the wheels and contacting theextreme ends of the teeth is a detent spring 87 having a serrated detentstone 88, the extreme edges of which are rounded to prevent wear on theteeth. The detent spring 87 is made long and flexible but has sufficientstrength to position either of the indexing wheels at half toothintervals. The indexing wheels 85 and 86 are located to bring theirteeth into the path of movement of the oscillating pin 84, thepositioning by the detent being such that the pin 84 engages a tooth ofone wheel when moving in one direction thereby moving each of the wheelsa half a tooth so that the pin will clear the teeth of that wheel andengage a tooth of the second wheel on its return swing again moving bothwheels the distance of half a tooth, thereby providing intermittentrotary motion in either direction depending on which wheel the pinion 23is attached. The present drawing shows the pinion 23 attached to thewheel 85 giving motion in a clockwise direction (Figure 4) to the pinion23.

'In. use, theelectric watch functions by reason of a periodic impulsedelivered as close as possible to the point of rest of the balanced.wheel by passing an electric current through a coil while said coil ismoving through a magnetic field of a particular direction set up by apair of permanent magnets which maybe made of Alnico V and a bridgingshunt. The angle of balance motion through which electrical energy istransformed into mechanical energy with a usable efiiciency is limitedby the angular distance the coil. moves when passing through theintensified magnetic field.

Referring to thediagrammatic showings in Figures 14-17, the permanentmagnets 48 and 49. are positioned so that a north pole is opposed to asouth pole and present leakage fields 92 and 93 respectively to magnets'48 and 49 and a field 94 common to both magnets. The shunt 50 ispositioned to bridge. the gap between: the two magnets and serves tointensify the. flow of magnetic fiux from the north pole of magnet: 48to the south pole. of magnet 49 providing the two intensified regions 96and 97 through which the coil passes. At the moment of energization ofthe. coil a magnetic field is produced, as shown in Figure 17, in whichthe cross marks 98 indicate a direction of magnetic flux into the paperand the dots 99 indicate a direction out from the paper. Thisdirectional flow of magnetic flux is indicated by the arrows 100 inFigure in the field 96 and in the direction of the arrows 101 in thefield 97. By examining Figure 15 it will be seen that the flow ofmagnetic flux in the permanent. magnetic field adds vectorially to theflow of the flux produced in the coil on the left edges of the coil, asshownin Figure 15, and subtracts on the right edges of the coil. Thiswill produce a force tending to move the coil toward the right (Figure15), the force acting simultaneously at two-places on the coil and inthe same direction.

The battery 46 through its ground 47 passing through the pillar plateand balance cock and hairspring to the balance staff and toone end ofthe coil delivers an elec tric' current uponthecompletion of the circuitthrough the other end of the coil, the contact 68, the contact makingarm 70, the spring 72, the bridge 77, and the return wireto the battery79. The'energizationof the coil in the interval it is passing throughthe magnetic fields between the ends of the magnets 48 and 49 and theshunt 50 imparts energy to the balance wheel 61 which in turn impartsrotary motion through the pin 84 to the indexing wheels 85 and 86,through the train of gears to the customary hands.

The energy thus imparted to the balance wheel once in each completecycle restores the energy expended by the wheel to overcome frictionallosses, windage losses and spring losses, as in the usual watch balance,and also the energy expended by the wheel in making electrical contactand in driving the train, in which features and especially in the last,the action is not the same as in the ordinary spring driven watch. Amotion is established at which equilibrium is maintained between theenergy expended and the energy supplied, and the balance wheel andhairspring combination act in the ordinary fashion, with the equilibriumenergy changing its form from kinetic energy of the wheel to potentialenergy in the spring and back again according to well defined laws withthe result that the oscillations are performed in equal times and thehands move with uniform velocity.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiment is therefore to be considered in all respects as illustrativeand not restrictive, the scope of the invention being indicated by theappended claims rather than by the foregoing description, and allchanges which come within the meaning and range of equivalency of theclaims are therefore intended to be embraced therein.

What is claimed is:

1. In a battery operated watch, a balance wheel. and staff assembly,means establishing a permanent magnetic field having two spacedintensified regions, a substantially planar coil carried by saidassembly and. arranged to have separate parts thereof simultaneouslypass through said intensified regions, the plane of said coil beingsub-- stantially perpendicular to said stafi, and means for periodicallyconnecting said coil with said battery to create a magnetic flux aboutsaid coil, said. intensified regions being so arranged that thereaction, between said flux and said intensified regions simultaneouslyimpulses said coil in each intensified region, the impulse in one regionurging the portion of' the coil. therein. in a first direction while:said impulse in the other region urges; the portion of the. coiltherein. in. a. second direction. which. differs from said firstdirection by some. angle other than;

2. In a battery operated electric watch, a balance wheel. and staffassembly, a coil wound about an axis normal. to said balance wheelcarried by said assembly, means. establishing a permanent magnetic fieldhaving two. intensified regions arranged to simultaneously pass through.spaced portions of said coil, and means for periodically connecting saidcoilwith said. battery, said coil being mounted for oscillation throughsaid magnetic field.

3. In a battery operated electric watch, a balance. wheel. and staffassembly, a coil carried by said balance wheel in an angular sectorthereof encompassing less than 180 means establishing a permanentmagnetic, field. having two. intensified regions so located as tosimultaneously pass. through spaced portions of said. coil, and meansfor, periodically connecting said coil. with said battery, said coilbeing mounted for oscillation. through said magnetic. field.

4. In a battery operated electric watch, a. balance wheel; and staffassembly, a coil carriedv by said assembly ec centrically of said staff,means, establishing a magnetic. field having two intensified regionsarranged to simul' taneously intersect spaced portions of; said coil,and means for periodically connecting said. coil. with said batterytocause impulsing of said spaced'portions of said. coil in. the samerotational direction.

5. In an electric watch, permanent magnet means, a pair of intensifiedmagnetic fields created by said magnet means, an oscillating balancewheel, a single coil carried by such wheel and having portionssubstantially radial to said wheel, the plane of rotation of said wheelbeing substantially normal to the flux of the intensified magneticfields, said fields being located within the circumference of saidwheel, means for energizing said coil simultaneously with its passagethrough said fields, whereby the interaction of said fields with themagnetic flux of said coil will produce the net torque on said balancewheel.

6. An electric watch as set out in claim 5 wherein said Wheel is carriedby a balance staff, a roller carried above the wheel, a second rollercarried below the wheel, the upper roller supporting a jewel pin and anelectrical contact, and the lower roller supporting an indexing pin.

7. In a battery operated electric Watch, a balance staff, asubstantially planar coil carried by said staff, the plane of said coilbeing perpendicular to said staff, means establishing a magnetic fieldhaving two intensified regions centered at positions spaced about saidstaff less than 180 apart, said coil having spaced portionssimultaneously positionable in said intensified regions, and means forperiodically connecting said coil With said battery, said coil beingmounted for oscillation through said magnetic field so that said spacedcoil portions receive simultaneous impulses from said intensifiedregions.

8. An electric watch as set out in claim 7 wherein said balance staffcarries a balance wheel and forms therewith a balance wheel and staffassembly comprising a framework having a hub, said coil being positionedby said framework, a roller carried above the wheel, a second rollercarried below the wheel, the upper roller supporting a jewel pin and anelectrical contact and the lower roller supporting an indexing pin.

9. An electric watch as set out in claim 8 wherein said coil has athickness in the direction of the axis of said staff substantially nogreater than the thickness of said framework in the same direction.

10. An electric watch as set out in claim 7 wherein said balance staffcarries a balance wheel and forms therewith a balance wheel and stafiassembly comprising a framework having a hub, said coil being carried bysaid framework and having a thickness in the direction of the axis ofsaid staff substantially no greater than the thickness of said frameworkin the same direction.

11. An electric watch as set out in claim 10 wherein said coil comprisesa pair of straight sides joined by arcuate coil portions.

12. In a battery operated electric watch, a balance staff, a coil woundabout an axis parallel to said staff, means establishing a magneticfield have two intensified regions arranged to simultaneously passthrough spaced portions of said coil, and means for periodicallyconnecting said coil with said battery, said coil being mounted foroscillation through said magnetic field.

13. A watch as set out in claim 12 wherein said balance staff carries abalance wheel and forms therewith a balance wheel and staff assemblycomprising a framework having a hub, said coil being positioned by saidframe work, a roller carried above the wheel, a second roller carriedbelow the wheel, the upper roller supporting a jewel pin and anelectrical contact and the lower roller supporting an indexing pin.

14. In a miniature battery operated isochronal device, a balance stafimounted for oscillation, a substantially planar coil carried by saidstaff with the plane of said coil perpendicular to said staff, meansestablishing a magnetic field having two intensified regions spacedabout said staff such a distance that spaced portions of said coil aresimultaneously positionable within said intensified regions, and meansfor periodically connecting said coil with said battery to providesimultaneous impulses to said spaced portions of said coil.

15. A device as set out in claim 14 wherein the magnetic axes of saidintensified regions are substantially parallel to said staif. i

16. A device as set out in claim 15 wherein said intensified regions arespaced about said staff by an angle of less than 17. A device as set outin claim 16 wherein said coil comprises a sector shaped coil mountedeccentrically of said stafi and having radial portions thereof formingsaid spaced portions.

18. A device as set out in claim 14 wherein said balance statf carries abalance wheel and forms therewith a balance wheel and staff assemblycomprising a framework having a hub, said coil being positioned by saidframework, a roller carried above the wheel, a second roller carriedbelow the wheel, the upper roller supporting a jewel pin and anelectrical contact and the lower roller supporting an indexing pin.

19. A device as set out in claim 18 wherein said coil has a thickness inthe direction of the axis of said stafi substantially no greater thanthe thickness of said framework in the same direction.

20. A device as set out in claim 14 wherein said balance stafi carries abalance wheel and forms therewith a balance wheel and staff assemblycomprising a framework having a hub, said coil being carried by saidframework and having a thickness in the direction of the axis of saidstaff substantially no greater than the thickness of said framework inthe same direction.

21. A device as set out in claim 20 wherein said coil comprises a pairof straight sides joined by arcuate coil portions.

References Cited in the file of this patent UNITED STATES PATENTS1,175,610 Cove Mar. 14, 1916 2,125,638 Hubert Aug. 2, 1938 2,577,703Fillinger Dec. 4, 1951 2,598,912 Held June 3, 1952 2,644,293 Black July7, 1953 2,662,366 Koehler Dec. 15, 1953 FOREIGN PATENTS 501,215 FranceJan. 19, 1920

